The present invention generally relates to an air conditioner system of a vehicle and more particularly relates to an improvement of a selectively controlled air blowing outlet system for blowing out the conditioned air from one or more preselected outlets formed in a heater unit at a time of, for instance, heating, cooling, or defrosting.
Basic construction of an air conditioner system is shown in FIG. 1 as for an example. It generally comprises an air intake box I housing a fan 2 and an air intake door 1 for switching between an outside air introduction and inside air recirculation, a cooling unit Co housing an evaporator 3 through which a coolant circulates when a compressor (not shown) of the cooling system operates, and a heater unit H. In the heater unit H, a heater core 4, through which the engine cooling water heated by the engine circulates, and an air mixing door 5 for controlling amount of air flow passing through the heater core 4 are arranged and air of suitably adjusted temperature is formed in a mixing chamber in the heater unit by mixing a hot air flow having passed through the heater core 4 and a cold air not having passed through the heater core 4 according to the opening of the air mixing door 5. Thus formed air of suitable temperature is blown out through outlets Bw leading to various portions in the cabin of a vehicle, for instance, a ventilator outlet 6, a heater outlet 7 or a defroster outlet 8. In the figure, 9 is a ventilator door and 10 is a floor door.
In such a kind of air conditioner system, a predetermined air outlet Bw should be selected for each operation mode, such as heating, cooling, etc. A typical conventional outlet selection control system will briefly be explained by referring to FIG. 2. In the heater unit H, a respective door Dr for opening or closing each of the outlets generally indicated by Bw is provided. For instance, a ventilator door 9 is provided for the ventilator outlet 6, a floor door 10 is provided for the heater outlet and a defroster door 11 is provided for the defroster outlet, respectively. Opening or closing of these doors 9, 10 and 11 is controlled respectively by a driving device generally indicated by K and each consists of vacuum actuator 12, 13 or 14 being provided individually. Each one of the vacuum actuators 12, 13 and 14 is provided with a pair of vacuum taps as shown by a', b', c', d', e' and f' and the actuator operates stepwise by the control signals fed from two systems. The supply of negative pressure to these vacuum taps a', b', c', d', e' and f' is effected by a vacuum selector 15. This vacuum selector 15 is drum shaped and it comprises 8 positions S', V', A', B', C', D', E' and F'. The position S' is connected with a vacuum source 16 of the engine manifold negative pressure. The positions A', B', C', D', E' and F' are connected to the vacuum taps a', b', c', d', e' and f' respectively through piping system. The position V' is connected to the open air. The positions A', B', C', D', E' and F' are arranged either to communicate with the negative pressure or to the open air. The vacuum selector 15 cooperates with the mode selector according to a predetermined program to establish a desired vacuum circuit.
A more practical operation diagram of this system is illustrated in the following tables 1 to 3.
TABLE 1 ______________________________________ Vacuum Mode selector VENT BI-LEVEL HEAT DEF ______________________________________ Vacuum source open air Position for ventilator door 9 Position for flood door 10 Position for defroster door 11 S' V' A' B' C' D' E' F' ##STR1## ##STR2## ##STR3## ##STR4## ##STR5## ##STR6## o ##STR7## ______________________________________ o-o: Communication
TABLE 2 ______________________________________ Vacuum Mode actuator VENT BI-LEVEL HEAT DEF ______________________________________ Position for a' o o x x ventilator door 9 b' o x x x Position for c' x o o x floor door 10 d' x x o x Position for e' o o o x defroster door 11 f' o o x x ______________________________________ o: Communication with negative pressure x: Open air
TABLE 3 ______________________________________ Mode Door VENT BI-LEVEL HEAT DEF ______________________________________ Ventilator door 9 Full open Half open Full close Full close Floor door 10 Full close Half open Full open Full close Defroster door 11 Full close Full close Half open Full open ______________________________________
Table 1 illustrates a program for representing the condition of the positions S', V', A', B', C', D', E' and F' of the vacuum selector 15 in case any one of the modes, i.e., ventilator mode (VENT), bi-level mode (BI-LEVEL), heat mode (HEAT) of the mode selector 17 is selected.
Table 2 illustrates the input condition of the negative pressure signal to the supply taps a, b, c, d, e and f of the vacuum actuator 12, 13 and 14 for each of the modes.
Table 3 shows the open or close condition of the doors 9, 10 and 11 for each of the modes.
In the Tables, for instance, a case when the ventilator mode (VENT) has been selected will be explained. In this case, as shown in the table 1, the positions A', B', E' and F' of the vacuum selector 15 are connected to the vacuum source 16, while the positions C' and D' are coupled to the open air. Therefore, as can be seen from tables 2 and 3, negative pressure is supplied to the supply taps a', b' and e', f' of the vacuum actuators 12 and 14, so that both these vacuum actuators 12 and 14 operate stepwise to fully open the ventilator door 9 and to fully close the defroster door 11. The negative pressure signal is not fed to the supply taps c' and d' of the vacuum actuator 13 and this vacuum actuator 13 remains unoperated and the floor door 10 is maintained in fully closed condition. Further, for example, in a heat mode (HEAT), among the supply taps e', f' of the vacuum actuator 14 for driving the defroster door 11, only the tap e' thereof is supplied with the negative pressure signal as shown in the tables 2 and 3, the vacuum actuator 14 operates one step and the defroster door 11 is settled in half-opened condition.
However, in such a kind of selectively controlled outlet system, as the means for selecting outlets Bw corresponding to the 4 modes, 3 vacuum actuators 12, 13 and 14 and a vacuum selector 15 having 8 positions S', V', A', B', C', D', E' and F' are required so that the number of lines in the piping system of the vacuum signal system becomes large and the program for setting the conditions corresponding to the modes of the positions S', V', A', B', C', D', E' and F' becomes complicated. The construction of the vacuum selector 15 itself may also becomes complicated and may not be realized by a simple mechanical overlapping of the communication ports and hence a more highly accurate controlling mechanism may be required. For instance, a three-way vacuum electromagnetic valve being controlled by an electric signal based on a program switch must be used. This results in a restriction in the space for mounting the device and it also causes an increase in the cost.